Configuring T1 Data Inversion
By default, data inversion is disabled. To enable data inversion at the HDLC level, include the invert-data statement at the [edit interfaces interface-name t1-options] hierarchy level:
When you enable data inversion, all data bits in the data stream are transmitted inverted; that is, zeroes are transmitted as ones and ones as zeroes. Data inversion is normally used only in AMI mode to guarantee ones density in the transmitted stream.